So yesterday the same thing happened to me. I tried the update, it didn't take long, just a few minutes, the update wasn't available, just the manual, so I let it download, halfway through the download (via wi-fi), the main display went out and the driver's display showed various warnings about problems. I tried turning the car off and on again - nothing, everything was locked incl. the gear lever.
It's my first hybrid, I didn't know what it was, I thought the car had somehow locked up in the software. I called Honda Assistance, they don't advise anything, they send a tow truck, the tow truck doesn't advise either (even though they could), they just load the car up and take it to the Honda service center.
The mechanic told me that it was a dead 12V battery. Apparently there is a fuse in the car that says that if the 12V battery is discharged below a certain level, the car simply won't go any further. He told me that all I had to do was use a jump starter (which
I have in my car, of course), and then drive the car to a place where the 12V battery can be recharged. A tow truck could have easily done it, and charged the battery only enough to put the car in "N" and load it. Because if they started the car, they would have lost money on the transport.
I was also told by the tow truck that they come out to "dead" hybrids quite often.
The mechanic told me that every time I enter the infotainment system (update, set up, tune the radio, etc.) the car must be started (or in EV mode - so that the engine can start right away), otherwise the 12V battery will discharge. And since it's really small, it will discharge pretty quickly.
It's quite disappointing to me that the 12V battery can discharge so quickly and cause such problems.
